From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yasunori Goto Date: Wed, 08 Mar 2006 13:42:03 +0000 Subject: [PATCH: 007/017](RFC) Memory hotplug for new nodes v.3. (refresh NODE_DATA() for ia64) Message-Id: <20060308212941.0030.Y-GOTO@jp.fujitsu.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Luck, Tony" , Andi Kleen , Joel Schopp , Dave Hansen Cc: linux-ia64@vger.kernel.org, Linux Kernel ML , linux-mm , Andrew Morton This is to refresh node_data[] array for ia64. As I mentioned previous patches, ia64 has copies of information of pgdat address array on each node as per node data. At v2, this function used stop_machine_run() to update them. (I wished that they were copied safety as much as possible.) But, in this patch, this arrays are just copied simply, and set node_online_map bit after completion of pgdat initialization. So, kernel must touch NODE_DATA() macro after checking node_online_map(). (Current code has already done it.) This is more simple way for just hot-add..... Note : It will be problem when hot-remove will occur, because, even if online_map bit is upset, kernel may touch NODE_DATA() due to race condition. :-( Signed-off-by: Yasunori Goto Index: pgdat6/arch/ia64/mm/discontig.c =================================--- pgdat6.orig/arch/ia64/mm/discontig.c 2006-03-06 18:26:07.000000000 +0900 +++ pgdat6/arch/ia64/mm/discontig.c 2006-03-06 18:26:11.000000000 +0900 @@ -308,6 +308,17 @@ static void __init reserve_pernode_space } } +void __meminit scatter_node_data(void) +{ + pg_data_t **dst; + int node; + + for_each_online_node(node){ + dst = LOCAL_DATA_ADDR(pgdat_list[node])->pg_data_ptrs; + memcpy(dst, pgdat_list, sizeof(pgdat_list)); + } +} + /** * initialize_pernode_data - fixup per-cpu & per-node pointers * @@ -320,11 +331,8 @@ static void __init initialize_pernode_da { int cpu, node; - /* Copy the pg_data_t list to each node and init the node field */ - for_each_online_node(node) { - memcpy(mem_data[node].node_data->pg_data_ptrs, pgdat_list, - sizeof(pgdat_list)); - } + scatter_node_data(); + #ifdef CONFIG_SMP /* Set the node_data pointer for each per-cpu struct */ for (cpu = 0; cpu < NR_CPUS; cpu++) { @@ -719,3 +727,9 @@ void __init paging_init(void) zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page)); } + +void arch_refresh_nodedata(int update_node, pg_data_t *update_pgdat) +{ + pgdat_list[update_node] = update_pgdat; + scatter_node_data(); +} Index: pgdat6/arch/ia64/Kconfig =================================--- pgdat6.orig/arch/ia64/Kconfig 2006-03-06 18:25:31.000000000 +0900 +++ pgdat6/arch/ia64/Kconfig 2006-03-06 18:26:11.000000000 +0900 @@ -364,6 +364,10 @@ config HAVE_ARCH_EARLY_PFN_TO_NID def_bool y depends on NEED_MULTIPLE_NODES +config HAVE_ARCH_NODEDATA_EXTENSION + def_bool y + depends on NUMA + config IA32_SUPPORT bool "Support for Linux/x86 binaries" help Index: pgdat6/include/asm-ia64/nodedata.h =================================--- pgdat6.orig/include/asm-ia64/nodedata.h 2006-03-06 18:24:02.000000000 +0900 +++ pgdat6/include/asm-ia64/nodedata.h 2006-03-06 18:26:11.000000000 +0900 @@ -47,6 +47,15 @@ struct ia64_node_data { */ #define NODE_DATA(nid) (local_node_data->pg_data_ptrs[nid]) +/* + * LOCAL_DATA_ADDR - This is to calculate each local_node_data address among hot-plug phase. + * When new node is hot-added, the addresses of local data for other nodes + * are necessary to be updated. In addtion, the cpu's on the new node + * will be initialized after this local_data initialization. So, + * per_cpu_page and local_node_data can't be used. + */ +#define LOCAL_DATA_ADDR(pgdat) ((struct ia64_node_data *)((u64)(pgdat) + L1_CACHE_ALIGN(sizeof(struct pglist_data)))) + #endif /* CONFIG_NUMA */ #endif /* _ASM_IA64_NODEDATA_H */ -- Yasunori Goto